Wafer-level blind hole filling method for metal nanoparticle mechanical centrifugal stacking-low-temperature heat treatment forming

Abstract

The invention discloses a wafer-level blind hole filling method for metal nanoparticle mechanical centrifugal stacking-low-temperature heat treatment forming, and belongs to the field of micro-nano manufacturing processes. The method comprises the following key steps: etching a blind hole (the diameter is 0.1-10 [mu] m, and the depth-to-width ratio is 5: 1-20: 1) on a wafer-level substrate, and preparing a barrier layer on an insulating layer in the hole; preparing a metal nanoparticle dispersion liquid, infiltrating the metal nanoparticle dispersion liquid to the surface of the blind hole, and improving the wettability between the inner wall of the blind hole and the metal nanoparticle dispersion liquid through the synergistic effect of an electric field and local gas discharge; dense stacking of the metal nanoparticles in the blind holes is realized through mechanical centrifugation and nanoparticle self-assembly; and finally, melting and rearranging the metal nanoparticles through low-temperature heat treatment to realize compact filling of the wafer-level blind hole. The compact filling of the small-aperture high-aspect-ratio wafer-level blind hole is realized through efficient generation of metal nanoparticle dispersion liquid, discharge enhanced electrowetting, metal nanoparticle mechanical centrifugal stacking and a low-temperature thermal forming technology, and the method has a wide application prospect in the fields of 3D advanced packaging, on-chip (on-chip) system integration and the like.

Description

Technical Field

[0001] The present invention discloses a wafer-level blind via filling method formed by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles, belonging to the fields of micro-nano manufacturing and integrated circuits. Background Art

[0002] The rapid development in fields such as artificial intelligence, high-performance computing, and global situation awareness has continuously raised the requirements for the performance of integrated chips. The advanced packaging technology based on through-hole interconnection has become the core technical direction for promoting the leapfrog development of chip performance with the advantage of high integration. The advanced through-hole interconnection technology realizes the vertical connection inside or between chips by drilling holes and filling conductive materials in the wafer-level substrate. This technology can significantly shorten the chip interconnection length and has advantages such as low power consumption, wide bandwidth, and high-speed communication. Although the through-hole interconnection technology brings many benefits, the contradiction between quality and cost in its metallization process remains the key limiting its wide application.

[0003] The metallization process of wafer-level interconnect vias mainly includes electroplating, chemical vapor deposition, vacuum reflow soldering, etc. Currently, electroplating filling is the mainstream method for wafer-level interconnect via metallization. However, as the blind hole diameter continues to decrease and the aspect ratio continues to increase, it is still a technical problem to prepare a continuous seed layer in the deep hole and regulate the synergistic effect among inhibitors, accelerators, and leveling agents in the electroplating solution. As the hole diameter gradually decreases and the aspect ratio continues to increase, the number of voids and defects of the metal filled in the electroplated holes increases, seriously affecting the performance and reliability of electronic devices. Although chemical vapor deposition can achieve precise control of the deposition thickness, its deposition rate is relatively slow, the material utilization rate is low, and the cost is high. The vacuum reflow soldering method fills in a vacuum environment, which can effectively reduce environmental pollution and is suitable for the deposition of various metals. However, this method has the problem of high equipment cost, and during the wafer-level blind via filling process, uneven filling is likely to occur, resulting in a low yield. If the traditional path is still used to transform the equipment and optimize the process for wafer-level blind via metallization, the manufacturing cost will increase sharply. Therefore, it is urgent to explore a new process route to create a wafer-level blind via metallization filling method with simplified process, optimized cost, and universality. Summary of the Invention

[0004] In view of the problems such as low filling rate of wafer-level blind vias, difficult wetting of via walls, and high metallization cost, the present invention proposes a method for filling wafer-level blind vias by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles. First, an insulating layer and a barrier layer are sequentially prepared in the wafer-level blind vias with high aspect ratio. Secondly, the metal nanoparticle dispersion is infiltrated onto the surface of the blind vias, and the wettability between the inner wall of the blind vias and the metal nanoparticle dispersion is improved through the synergistic effect of an electric field and local gas discharge. Then, dense stacking of nanoparticles in the blind vias is achieved by mechanical centrifugation and self-assembly of nanoparticles. Finally, in an inert gas atmosphere, heat treatment is performed on the wafer-level blind vias with dense stacking of metal nanoparticles, so that the metal nanoparticles are melted and rearranged to achieve dense filling of the wafer-level blind vias. The diameter of the metal nanoparticles ranges from 5 nm to 150 nm, which greatly reduces the melting temperature of the metal, thereby realizing the melting and rearrangement of metal grains under low-temperature conditions.

[0005] The purpose of the present invention is to provide a method for filling wafer-level blind vias by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles. First, blind vias are etched on a wafer-level substrate, and an insulating layer and a barrier layer are sequentially prepared. Secondly, the wettability between the inner wall of the blind vias and the metal nanoparticle dispersion is improved through the synergistic effect of an electric field and local gas discharge. Then, the metal nanoparticle dispersion prepared by chemical reduction method is infiltrated onto the surface of the electrowetted blind vias, and dense stacking of metal nanoparticles in the blind vias is achieved by mechanical centrifugation and self-assembly of nanoparticles. Finally, in an inert gas atmosphere, heat treatment is performed on the blind vias with dense stacking of metal nanoparticles to obtain wafer-level blind vias filled with dense metal. The specific preparation method includes the following steps:

[0006] (1) Etch blind vias (with a diameter of 0.1 μm to 10 μm and an aspect ratio of 5:1 to 20:1) on a wafer-level substrate;

[0007] (2) Sputter-deposit a barrier layer (which can be nickel, titanium, chromium, titanium nitride, or alumina, etc.) with a thickness of 10 nm to 500 nm on the insulating layer (which can be silica, glass, silicon nitride, or alumina, etc.) of the blind vias;

[0008] (3) Infiltrate the metal nanoparticle dispersion prepared by chemical reduction method onto the surface of the blind vias, and improve the wettability between the inner wall of the blind vias and the metal nanoparticle dispersion through the synergistic effect of an electric field and local gas discharge;

[0009] (4) Achieve dense stacking of nanoparticles in the blind vias through mechanical centrifugation and self-assembly of nanoparticles;

[0010] (5) In an inert gas atmosphere, perform heat treatment (50 °C to 400 °C) on the blind vias with dense stacking of metal nanoparticles, and the metal nanoparticles are melted at low temperature to obtain wafer-level blind vias filled with dense metal.

[0011] Preferably, the substrate material of the present invention is silicon, glass, silicon nitride, aluminum nitride, aluminum oxide, diamond, silicon carbide, graphene, organic resin (such as polyimide, epoxy resin), and composites of organic resin and inorganic fillers.

[0012] Preferably, the insulating layer of the present invention is one or more of silicon dioxide, glass, silicon nitride, or aluminum oxide.

[0013] Preferably, the barrier layer of the present invention is one or more of nickel, titanium, chromium, titanium nitride, or aluminum oxide.

[0014] Preferably, the method for filling blind holes by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles of the present invention is characterized in that the metal nanoparticles are one or more of copper, nickel, silver, gold, copper-silver alloy, and copper-tin alloy.

[0015] Preferably, the diameter of the metal nanoparticles of the present invention is 5 nm to 150 nm;

[0016] Preferably, the reducing agent in the metal nanoparticle dispersion of the present invention is a reagent such as sodium hypophosphite, ascorbic acid, or sodium borohydride, the metal nanoparticle dispersant is a reagent such as polyvinylpyrrolidone, sodium dodecyl sulfate, or polyethylene glycol, and the pH regulator is a reagent such as sulfuric acid, hydrochloric acid, or sodium hydroxide.

[0017] Preferably, the metal nanoparticle dispersion and the discharge-enhanced electro-wetting of the blind holes of the present invention use an alternating current power supply with a frequency of 20 Hz to 5 kHz and a voltage range of 2 V to 2000 V.

[0018] Compared with the prior art through the above technical solutions conceived by the present invention, the following obvious improvements can be achieved:

[0019] (1) Compared with conventional wetting technologies such as plasma treatment and solution soaking, the discharge-enhanced electro-wetting technology performs more excellently in improving the pre-wetting effect of the hole wall and can more effectively optimize the densification of metal filling. In the discharge-enhanced electro-wetting process, the synergistic effect of the electric field and local gas discharge causes the dynamic contact angle at the interface between the droplet and the hole wall to be greatly reduced, and the metal nanoparticle dispersion can more easily overcome the capillary resistance and enter the hole. At the same time, this technology effectively eliminates the phenomenon of droplet accumulation at the hole opening, promotes the rapid migration of bubbles in the hole to the outside of the hole, and avoids the risk of interface defects caused by bubble retention.

[0020] (2) Compared with conventional blind via metallization methods such as electroplating, the method of forming and filling metal nanoparticles by mechanical centrifugal stacking - low - temperature heat treatment abandons the difficult process of preparing a continuous seed layer in small - aperture and high - aspect - ratio wafer - level blind vias. At the same time, there is no need to perform complex ratio regulation on the additives in the electroplating solution, greatly reducing the difficulty and cost of blind via metallization. Brief Description of the Drawings

[0021] Figure 1 Flow chart of a wafer - level blind via filling method for forming metal nanoparticles by mechanical centrifugal stacking - low - temperature heat treatment;

[0022] Figure 1 In the figure: 1 - Substrate; 2 - Coating photoresist; 3 - Lithography pattern; 4 - Etching blind via; 5 - Cleaning photoresist and impurities; 6 - Preparing insulating layer; 7 - Depositing barrier layer; 8 - Densely stacking metal nanoparticles; 9 - Melting and rearranging metal nanoparticles;

[0023] Figure 2 Schematic diagram of discharge - enhanced electro - wetting;

[0024] Figure 2 In the figure: 1 - Plasma discharge; 2 - Metal nanoparticles;

[0025] Figure 3 Schematic diagram of a centrifugal device

[0026] Figure 4 Schematic diagram of the low - temperature heat treatment forming process;

[0027] Figure 4 In the figure: 1 - Metal nanoparticles; 2 - Heat treatment;

[0028] Figure 5 Morphology diagram of copper nanoparticles in a copper nanoparticle dispersion;

[0029] Figure 6 Optical microscope image of copper nanoparticles densely filling a blind via; Detailed Description of the Invention

[0030] The present invention will be further described in detail below with reference to the drawings and specific embodiments, but the protection scope of the present invention is not limited to the content described.

[0031] Example 1

[0032] A wafer - level blind via filling method for forming metal nanoparticles by mechanical centrifugal stacking - low - temperature heat treatment specifically includes the following steps:

[0033] (1) Etch blind vias (diameter is 0.1 μm, aspect ratio is 5:1) on a silicon wafer;

[0034] (2) Deposit a 10-nm-thick silicon dioxide insulating layer by plasma-enhanced chemical vapor deposition and a 10-nm-thick titanium barrier layer by sputtering deposition.

[0035] (3) Infiltrate the surface of the blind holes with the dispersion of copper nanoparticles (particle diameter 5 nm - 20 nm) prepared by chemical reduction method. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the dispersion of copper nanoparticles. For discharge-enhanced electro-wetting, an AC power supply is selected with a frequency of 5 KHz and a voltage of 200 V.

[0036] (4) Achieve dense stacking of copper nanoparticles in the blind holes through mechanical centrifugation and self-assembly of nanoparticles. Among them, in the composition of the copper nanoparticle suspension, the concentration of CuSO 4 ·5H 2 O is 50 g / L, the concentration of H 2 SO 4 is 0.2 g / L, the concentration of HCl is 0.05 g / L, the concentration of NaH 2 PO 2 ·H 2 O is 40 g / L, and the concentration of (C 6 H 9 NO) n is 1 g / L.

[0037] (5) In an argon atmosphere, perform heat treatment (100 °C) on the blind holes with dense stacking of copper nanoparticles, and the copper nanoparticles are melted at low temperature to obtain wafer-level blind holes filled with dense metal.

[0038] Example 2

[0039] A method for filling wafer-level blind holes by mechanical centrifugation stacking - low-temperature heat treatment of metal nanoparticles specifically includes the following steps:

[0040] (1) Etch blind holes (diameter 1 μm, depth-to-width ratio 10:1) on a silicon wafer.

[0041] (2) Deposit a 50-nm-thick silicon dioxide insulating layer by plasma-enhanced chemical vapor deposition and a 50-nm-thick nickel barrier layer by sputtering deposition.

[0042] (3) Infiltrate the surface of the blind holes with the dispersion of copper nanoparticles (particle diameter 5 nm - 50 nm) prepared by chemical reduction method. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the dispersion of copper nanoparticles. For discharge-enhanced electro-wetting, an AC power supply is selected with a frequency of 3 KHz and a voltage of 100 V.

[0043] (4) Achieve dense stacking of copper nanoparticles in the blind holes through mechanical centrifugation and self-assembly of nanoparticles. Among them, in the composition of the copper nanoparticle suspension, the concentration of CuSO 4·5H 2 The concentration of O is 100 g / L, and H 2 SO 4 has a concentration of 0.5 g / L, the concentration of HCl is 0.01 g / L, and NaH 2 PO 2 ·H 2 O has a concentration of 80 g / L, and (C 6 H 9 NO) n has a concentration of 2 g / L;

[0044] (5) In an argon atmosphere, heat-treat the blind holes densely stacked with copper nanoparticles at 200 °C, and the copper nanoparticles are melted at low temperature to obtain wafer-level blind holes filled with dense metal.

[0045] Example 3

[0046] A method for filling wafer-level blind holes by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles specifically includes the following steps:

[0047] (1) Etch blind holes (with a diameter of 10 μm and an aspect ratio of 20:1) on a silicon wafer;

[0048] (2) Thermally oxidize to grow a silicon dioxide insulating layer with a thickness of 100 nm, and sputter-deposit a titanium nitride barrier layer with a thickness of 500 nm;

[0049] (3) Infiltrate the dispersion of copper nanoparticles prepared by chemical reduction method onto the surface of the blind holes. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the dispersion of copper nanoparticles (particle diameter is 5 - 150 nm). For enhanced electro-wetting by discharge, an alternating current power supply is selected, with a frequency of 200 Hz and a voltage of 2 V;

[0050] (4) Achieve dense stacking of nanoparticles in the blind holes through mechanical centrifugation and self-assembly of nanoparticles. Among them, in the composition of the copper nanoparticle suspension, CuSO 4 ·5H 2 O has a concentration of 200 g / L, and H 2 SO 4 has a concentration of 2 g / L, the concentration of HCl is 0.03 g / L, and NaH 2 PO 2 ·H 2 O has a concentration of 160 g / L, and (C 6 H 9 NO) n has a concentration of 5 g / L;

[0051] (5) Heat-treat the blind holes densely stacked with copper nanoparticles in an argon atmosphere (300 °C), and the copper nanoparticles are melted at low temperature to obtain wafer-level blind holes filled with dense metal.

[0052] Example 4

[0053] A method for filling wafer-level blind holes by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles specifically includes the following steps:

[0054] (1) Etch blind holes (with a diameter of 0.1 μm and an aspect ratio of 5:1) on the wafer-level glass;

[0055] (2) Sputter-deposit a titanium barrier layer with a thickness of 10 nm;

[0056] (3) Infiltrate the dispersion of copper nanoparticles (particle diameter of 5 nm to 20 nm) prepared by chemical reduction method onto the surface of the blind holes. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the copper nanoparticle dispersion. For enhanced electro-wetting by discharge, an alternating current power supply is selected, with a frequency of 5 KHz and a voltage of 200 V;

[0057] (4) Achieve dense stacking of copper nanoparticles in the blind holes through mechanical centrifugation and nanoparticle self-assembly. Among them, the composition of the copper nanoparticle suspension has a concentration of CuSO 4 ·5H 2 O of 50 g / L, a concentration of H 2 SO 4 of 0.2 g / L, a concentration of HCl of 0.05 g / L, a concentration of NaH 2 PO 2 ·H 2 O of 40 g / L, and a concentration of (C 6 H 9 NO) n of 1 g / L;

[0058] (5) Heat-treat the blind holes densely stacked with copper nanoparticles in an argon atmosphere (100 °C), and the copper nanoparticles are melted at low temperature to obtain wafer-level blind holes filled with dense metal.

[0059] Example 5

[0060] A method for filling wafer-level blind holes by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles specifically includes the following steps:

[0061] (1) Etch blind holes (with a diameter of 1 μm and an aspect ratio of 10:1) on the wafer-level glass;

[0062] (2) Sputter-deposit a nickel barrier layer with a thickness of 50 nm;

[0063] (3) Infiltrate the dispersion of copper nanoparticles (particle diameter 5 nm - 50 nm) prepared by chemical reduction method onto the surface of the blind holes. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the copper nanoparticle dispersion. For discharge-enhanced electro-wetting, an alternating current power supply is selected, with a frequency of 3 kHz and a voltage of 100 V;

[0064] (4) Achieve dense stacking of copper nanoparticles in the blind holes through mechanical centrifugation and nanoparticle self-assembly. Among them, in the composition of the copper nanoparticle suspension, the concentration of CuSO 4 ·5H 2 O is 100 g / L, the concentration of H 2 SO 4 is 0.5 g / L, the concentration of HCl is 0.01 g / L, the concentration of NaH 2 PO 2 ·H 2 O is 80 g / L, and the concentration of (C 6 H 9 NO) n is 2 g / L;

[0065] (5) In an argon atmosphere, perform heat treatment (200 °C) on the blind holes with dense stacking of copper nanoparticles, and obtain wafer-level blind holes filled with dense metal by low-temperature melting of copper nanoparticles.

[0066] Example 6

[0067] A method for filling wafer-level blind holes by mechanical centrifugation stacking - low-temperature heat treatment of metal nanoparticles specifically includes the following steps:

[0068] (1) Etch blind holes (diameter 10 μm, depth-to-width ratio 20:1) on wafer-level glass;

[0069] (2) Sputter deposit a titanium nitride barrier layer with a thickness of 500 nm;

[0070] (3) Infiltrate the dispersion of copper nanoparticles (particle diameter 5 nm - 150 nm) prepared by chemical reduction method onto the surface of the blind holes. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the copper nanoparticle dispersion. For discharge-enhanced electro-wetting, an alternating current power supply is selected, with a frequency of 200 Hz and a voltage of 2 V;

[0071] (4) Achieve dense stacking of copper nanoparticles in the blind holes through mechanical centrifugation and nanoparticle self-assembly. Among them, in the composition of the copper nanoparticle suspension, the concentration of CuSO 4 ·5H 2 O is 200 g / L, the concentration of H 2 SO 4 is 2 g / L, the concentration of HCl is 0.03 g / L, the concentration of NaH 2PO 2 ·H 2 The concentration of O is 160 g / L, and the concentration of (C 6 H 9 NO) n is 5 g / L;

[0072] (5) In an argon atmosphere, the blind holes densely stacked with copper nanoparticles are heat-treated (300 °C), and the copper nanoparticles are melted at low temperature to obtain wafer-level blind holes filled with dense metal.

[0073] Example 7

[0074] A method for filling wafer-level blind holes by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles, specifically including the following steps:

[0075] (1) Etch blind holes (diameter 0.1 μm, aspect ratio 5:1) on wafer-level diamond;

[0076] (2) Plasma-enhanced chemical vapor deposition of a 10-nm-thick silicon nitride insulating layer, and sputter deposition of a 10-nm-thick titanium barrier layer;

[0077] (3) Immerse the dispersion of copper nanoparticles (particle diameter 5 nm - 20 nm) prepared by chemical reduction method on the surface of the blind holes. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the copper nanoparticle dispersion. The alternating current power supply is selected for discharge-enhanced electro-wetting, with a frequency of 5 KHz and a voltage of 200 V;

[0078] (4) Dense stacking of copper nanoparticles in the blind holes is achieved through mechanical centrifugation and self-assembly of nanoparticles. Among them, in the composition of the copper nanoparticle suspension, the concentration of CuSO 4 ·5H 2 O is 50 g / L, the concentration of H 2 SO 4 is 0.2 g / L, the concentration of HCl is 0.05 g / L, the concentration of NaH 2 PO 2 ·H 2 O is 40 g / L, and the concentration of (C 6 H 9 NO) n is 1 g / L;

[0079] (5) In an argon atmosphere, the blind holes densely stacked with copper nanoparticles are heat-treated (100 °C), and the copper nanoparticles are melted at low temperature to obtain wafer-level blind holes filled with dense metal.

[0080] Example 8

[0081] A wafer-level blind via filling method formed by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles, specifically including the following steps:

[0082] (1) Etch blind vias (with a diameter of 1 μm and an aspect ratio of 10:1) on wafer-level diamond;

[0083] (2) Plasma-enhanced chemical vapor deposition of a 50-nm-thick silicon nitride insulating layer and sputter deposition of a 50-nm-thick nickel barrier layer;

[0084] (3) Infiltrate the dispersion of copper nanoparticles (particle diameter of 5 nm to 50 nm) prepared by chemical reduction method onto the surface of the blind vias. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind vias and the copper nanoparticle dispersion. For discharge-enhanced electro-wetting, an AC power supply is selected, with a frequency of 3 KHz and a voltage of 100 V;

[0085] (4) Achieve dense stacking of copper nanoparticles in the blind vias through mechanical centrifugation and nanoparticle self-assembly. Among them, in the composition of the copper nanoparticle suspension, the concentration of CuSO 4 ·5H 2 O is 100 g / L, the concentration of H 2 SO 4 is 0.5 g / L, the concentration of HCl is 0.01 g / L, the concentration of NaH 2 PO 2 ·H 2 O is 80 g / L, and the concentration of (C 6 H 9 NO) n is 2 g / L;

[0086] (5) In an argon atmosphere, perform heat treatment (200 °C) on the blind vias with dense stacking of copper nanoparticles, and the copper nanoparticles are melted at low temperature to obtain wafer-level blind vias filled with dense metal.

[0087] Example 9

[0088] A wafer-level blind via filling method formed by mechanical centrifugal stacking and low-temperature heat treatment of metal nanoparticles, specifically including the following steps:

[0089] (1) Etch blind vias (with a diameter of 10 μm and an aspect ratio of 20:1) on wafer-level diamond;

[0090] (2) Plasma-enhanced chemical vapor deposition of a 100-nm-thick silicon nitride insulating layer and sputter deposition of a 500-nm-thick titanium nitride barrier layer;

[0091] (3) Immerse the dispersion of copper nanoparticles (particle diameter: 5 nm to 150 nm) prepared by chemical reduction method onto the surface of the blind holes. Through the synergistic effect of electric field and local gas discharge, improve the wettability between the inner wall of the blind holes and the copper nanoparticle dispersion. For discharge-enhanced electro-wetting, an AC power supply is selected, with a frequency of 200 Hz and a voltage of 2 V;

[0092] (4) Achieve dense stacking of copper nanoparticles in the blind holes through mechanical centrifugation and nanoparticle self-assembly. Among them, in the composition of the copper nanoparticle suspension, the concentration of CuSO 4 ·5H 2 O is 200 g / L, the concentration of H 2 SO 4 is 2 g / L, the concentration of HCl is 0.03 g / L, the concentration of NaH 2 PO 2 ·H 2 O is 160 g / L, and the concentration of (C 6 H 9 NO) n is 5 g / L;

[0093] (5) In an argon atmosphere, perform heat treatment (300 °C) on the blind holes with dense stacking of copper nanoparticles, and the copper nanoparticles are melted at low temperature to obtain wafer-level blind holes filled with dense metal.

Claims

1. A wafer-level blind hole filling method formed by mechanical centrifugal stacking of metal nanoparticles and low-temperature heat treatment, characterized in that: The specific steps include: (1) Etching blind holes (diameter of 0.1 μm to 10 μm, aspect ratio of 5:1 to 20:1) on the wafer substrate; (2) sputtering a barrier layer (which may be nickel, titanium, chromium, titanium nitride or aluminum oxide, etc.) with a thickness of 10 nm to 500 nm on the insulating layer (which may be silicon dioxide, glass, silicon nitride or aluminum oxide, etc.) of the blind hole; (3) infiltrating the metal nanoparticle dispersion prepared by chemical reduction method into the surface of wafer-level blind holes, and improving the wettability of the inner wall of the blind hole and the metal nanoparticle dispersion through the synergistic effect of electric field and local gas discharge; (4) Dense stacking of nanoparticles in wafer-level blind holes is achieved through mechanical centrifugation and nanoparticle self-assembly; (5) In an inert gas atmosphere, the wafer-level blind vias with densely stacked metal nanoparticles are heat treated (50°C to 400°C) to obtain densely metal-filled wafer-level blind vias by low-temperature melting of the metal nanoparticles.

2. According to claim 1, a wafer-level blind hole filling method of metal nanoparticle mechanical centrifugal stacking-low temperature heat treatment molding is characterized in that: The wafer-level substrate material is silicon, glass, silicon nitride, aluminum nitride, aluminum oxide, diamond, silicon carbide, graphene, organic resin (such as polyimide, epoxy resin) and a composite material of organic resin and inorganic filler.

3. According to claim 1, a wafer-level blind hole filling method of metal nanoparticle mechanical centrifugal stacking-low temperature heat treatment molding is characterized in that: The insulating layer is one or more of silicon dioxide, glass, silicon nitride or aluminum oxide.

4. The wafer-level blind hole filling method of metal nanoparticle mechanical centrifugal stacking-low temperature heat treatment molding according to claim 1 is characterized in that: The barrier layer is one or more of nickel, titanium, chromium, titanium nitride or aluminum oxide.

5. The wafer-level blind hole filling method of metal nanoparticle mechanical centrifugal stacking-low temperature heat treatment molding according to claim 1, characterized in that: The metal nanoparticles are one or more of copper, nickel, silver, gold, copper-silver alloy and copper-tin alloy.

6. The wafer-level blind hole filling method of metal nanoparticle mechanical centrifugal stacking-low temperature heat treatment molding according to claim 1, characterized in that: The diameter of the metal nanoparticles can be set to 5nm to 150nm.

7. The wafer-level blind hole filling method of metal nanoparticle mechanical centrifugal stacking-low temperature heat treatment molding according to claim 1, characterized in that: The reducing agent in the metal nanoparticle dispersion is sodium hypophosphite, ascorbic acid or sodium borohydride, the metal nanoparticle dispersant is polyvinyl pyrrolidone, sodium dodecyl sulfate or polyethylene glycol, and the pH regulator is sulfuric acid, hydrochloric acid or sodium hydroxide.

8. The wafer-level blind hole filling method of metal nanoparticle mechanical centrifugal stacking-low temperature heat treatment molding according to claim 1, characterized in that: The discharge enhanced electrowetting of the metal nanoparticle dispersion and blind holes uses an alternating current power supply with a frequency of 20 Hz to 5 KHz and a voltage range of 2V to 2000V.

Images